Highly precise and accurate measurements of pH and alkalinity have become key scientific techniques to understand how rising anthropogenic CO2 emissions are affecting calcification processes on coral reefs. Hence to make high frequency (hourly) measurements of using the potentiometric method is time consuming and tedious. Thus, pH and alkalinity are two important parameters of carbonate system that can be easily measured using the developed pH-alkalinity system.
In this study we have developed a method of utilising purified Bromophenol Blue (BPB) as an indicator to make simple one-point alkalinity measurements with spectrophotometric detection. The developed method was then used for dome experiments to monitor fluxes of carbonate production and dissolution at One Tree Island reef (Queensland, Australia). The developed automated pH-alkalinity system was used for laboratory and field experiments which had greater precision and accuracy. Thus, the automated system will be an essential tool for scientists to monitor changes in coral calcification rates and understand the impact of ocean acidification on marine environments.